Peter Thiel, the Silicon Valley billionaire and outspoken Donald Trump supporter, is considering a 2018 bid for California governor, according to three Republicans familiar with his thinking.

Thiel, who co-founded PayPal and was an early investor in Facebook, has been discussing a prospective bid with a small circle of advisers, including Rob Morrow, who has emerged as his political consigliere.

Morrow has worked at Clarium Capital, the San Francisco-based investment management firm and hedge fund that Thiel started.

Those who have been in touch with the 49-year-old entrepreneur are skeptical that he'll enter the race. He is a deeply private figure, and California is unfriendly territory for a Republican – particularly a pro-Trump one. The president-elect won just over 30 percent of the vote there.

But they add that Thiel has conspicuously yet to rule out a bid and that those around him continue to discuss it.